<style>
	.demo_css_sprt, .demo_css_sprt div	{
		border: 1px dotted red;
		padding:1em;
	}
	.demo_css_sprt div	{
		margin: 1em 0;
	}
	.demo_css_sprt p	{
		border: 1px dashed blue;
		padding:1em;
	}
	.demo_css_sprt .ab:first-letter	{
		font-size: 20px;
		font-weight: bold;
		color: red;
	}
</style>
<div class="demo_css_sprt">
	要素1
	<div class="ab">要素2</div>
	<div class="cd">要素3</div>
	<p class="ef">要素4</p>
</div>